1. Field of the Invention
The invention relates to an apparatus for performing chemical vapor deposition. More particularly, the invention relates to a lid assembly for distributing gases within a chemical vapor deposition system having a plurality of chambers.
2. Description of the Background Art
Chemical vapor deposition, or CVD, is a well-known and practiced technique for the deposition of material on a substrate such as a semiconductor wafer. A CVD chamber is typically defined by electrically grounded walls and a lid. A pedestal for supporting a substrate is disposed within the chamber. A showerhead is disposed beneath the lid and above the pedestal. Coupled to the chamber is a gas panel and, for process conditions above atmospheric pressure (i.e., high-pressure systems), optionally a RF source. The gas panel is coupled to the showerhead and provides process and other gases to the chamber. The process gases and substrate are preheated to a temperature that facilitates thermal decomposition of the gases and substrate film formation. In high-pressure systems, the showerhead is coupled to the RF source. When used, the RF source drives the showerhead, igniting and sustaining a process gas plasma that enhances the deposition process for plasma-enhanced CVD (PECVD). Deposition occurs when the process gas or gases injected into the chamber react to form a layer of material upon the substrate. As the formed material is often additionally deposited on components within the CVD chamber other than the wafer, the gas panel typically also supplies a cleaning agent such as Fluorine to clean or xe2x80x9cscrubxe2x80x9d the chamber of unwanted deposition material remaining after wafer processing.
Although CVD remains a key process in the sequence of most integrated circuit manufacturing, pressure to create more robust, reliable, and cost effective processing equipment has increased with greater competition and pricing pressure within the integrated circuit manufacturing trade. One solution has been to use multi-chamber, or cluster tools. Although this solution increases system throughput, each chamber has a dedicated Fluorine source to facilitate cleaning processes. This redundancy of hardware among chambers increases system capital costs. Additionally, as more components comprise a system, the likelihood of service and downtime frequency increases as well. For example, systems that incorporate a dedicated plasma generation source can be particularly problematic as microwave magnetrons have a tendency to require service often.
Therefore, a need exists in the art for apparatus for CVD processing that provides increased reliability while reducing the overall system hardware costs.
The disadvantages of the prior art are overcome by the present invention of an apparatus for distributing gases in a chemical vapor deposition (CVD) system. In one aspect of the invention, a lid assembly for a semiconductor processing apparatus having at least two chambers comprises a lid plate having a first side and a second side and a plasma generation source mounted to the first side of the lid plate. Additionally, at least two gas boxes are coupled to the first side of the lid plate, and a divider is coupled between the plasma generation source and the at least two gas boxes.
In another aspect of the invention, a semiconductor processing apparatus comprises at least two chambers and a lid assembly disposed over the at least two chambers. The lid assembly comprises a lid plate having a first side and a second side, and a plasma generation source mounted to the first side of the lid plate. Additionally, at least two gas boxes are coupled to the first side of the lid plate, and a divider is coupled to the plasma generation source and the at least two gas boxes.